Stapler for mucosectomy

ABSTRACT

The head of a stapler for mucosectomy comprises an external goblet-shaped body ( 1 ) wherein an internal goblet-shaped body ( 2 ) is concentrically and slidingly located, at the edge of which a circular blade ( 3 ) is fixed. The internal goblet-shaped body ( 2 ) is provided with a central hole ( 5 ) wherein a rod ( 6 ) is slidingly inserted, at the end ( 7 ) of which an anvil ( 8; 8 ′) is fixed. One or more annular grooves ( 11 ), which are parallel and suitably spaced one from the other, are formed on the lateral surface of the rod ( 6 ) perpendicularly to the axis thereof. Said grooves ( 11 ) are intended to receive a portion of mucosa ( 9   a ) which is included in a purse string suture as the mucosa is tied around the rod ( 6 ). By retracting the rod ( 6 ) in the central hole ( 5 ) of the stem ( 2   a ) of the internal goblet-shaped body ( 2 ) the mucosa to be removed is carried into the internal goblet-shaped body ( 2 ). The anvil ( 8; 8 ′) and the circular blade ( 3 ) are moved closer one to the other, by suitable means, in order to cut the tissues when the stapler is in a closed position.

The present invention relates to a stapler for mucosectomy in hollow organs and, more particularly, a type of stapler which is provided with a central grooved rod allowing to carry out a precise mucosectomy of a larger volume of mucosal tissue.

Mucosectomy is an operation which is particularly suited for the treatment of haemorrhoids, rectocele and rectal mucosal prolapse. Circular mechanical staplers are already known, both for applying staples and for applying compression devices such as e.g. fragmentable rings. Said staplers are provided with a central shaft. The objective of mucosectomy is to remove a portion of mucosa which is as large as possible, so as to ensure a remarkable “lifting” of the mucosa of the hollow organ.

In order to achieve this objective, in U.S. Pat. No. 6,102,271 a circular stapler is disclosed whose head comprises two concentric goblet-shaped bodies. Two through openings are provided on the lateral surface of said goblet-shaped bodies, in the proximity of the stems thereof. The through openings allow the purse-string suture thread to pass outwards therethrough. The suture thread can thus be pulled towards the outside of the above mentioned goblet-shaped bodies so as to drag into the inside thereof a volume of mucosa which is as large as possible. The mucosa is then cut by a circular blade which is fixed to the edge of the internal goblet-shaped body. At the same time, a shaft which is centrally arranged relative to the goblet-shaped bodies moves an anvil which is fixed to the end of the shaft in the proximity of the edge of the external goblet-shaped body for applying suture staples. However, the stapler described in the above mentioned patent has the drawback that the manual pulling of the suture threads during the step of closing the stapler does not allow to remove the mucosa in a homogeneous and controlled way with exactness.

Object of the present invention is thus to provide a stapler for mucosectomy which is free from such drawbacks. Said object is achieved by a stapler whose main characteristics are specified in the first claim, while other characteristics are specified in the subsequent claims.

In order to achieve said object, the stapler according to the present invention is provided with a central rod having one or more annular grooves formed on its lateral surface crosswise to its axis. Such grooves are intended to receive a portion of tissue when a purse-string suture is tied around the rod, as well as to prevent said portion of tissue from undesirably sliding along the central rod as the latter is retracted inside the stem of the internal goblet-shaped body. In order to ensure that during said retraction of the rod the hollow body wall is dragged in a controlled and homogeneous way into the internal goblet-shaped body, said grooves are suitably dimensioned and exactly spaced one from the other.

Another advantage provided by the stapler according to the present invention is to allow a precise removal of different amounts of mucosa simply by selecting a certain annular groove among those formed and calibrated on the rod of the stapler.

Further advantages and characteristics of the stapler according to the present invention will be evident to those skilled in the art from the following detailed and non-limiting disclosure of two embodiments thereof with reference to the annexed drawings wherein:

FIG. 1 is a partially sectioned side view of the head of a first embodiment of the stapler according to the present invention in an open position;

FIG. 2 is a longitudinally sectioned view of the head of the stapler in FIG. 1 being introduced inside a partially sectioned hollow organ through a hollow cylindrical introducer;

FIG. 3 is a longitudinally sectioned view of the head of the stapler in a closed position inside a hollow organ through a hollow cylindrical introducer;

FIG. 4 is a partially sectioned side view of the head of a second embodiment of the stapler according to the present invention in an open position;

FIG. 5 is an axonometric view of the head of the stapler of FIG. 4 in a closed position being introduced inside a partially sectioned hollow organ through a hollow cylindrical introducer; and

FIG. 6 is a longitudinally sectioned view of the head of the stapler of FIG. 5.

FIGS. 1 and 2 show a head of a stapler comprising in a known way an external goblet-shaped body 1, being provided with a first hollow stem 1 a, wherein a smaller internal goblet-shaped body 2 is concentrically and slidingly provided. A circular blade 3 is fixed to the edge of said internal goblet-shaped body 2. In a retracted position of the internal goblet-shaped body 2, the circular blade 3 is located inside the external goblet-shaped body 1 without protruding from the edge 4 of the latter. At the opposite side with respect to the circular blade 3 the internal goblet-shaped body 2 has a second hollow stem 2 a which is provided with a central hole 5 wherein a rod 6 is slidingly inserted. In correspondence to the part which is opposite to the one where the central hole 5, wherein the rod 6 slides, is located, the rod 6 has an end 7 to which an anvil 8 is fixed. The hollow stem 1 a of the external goblet-shaped body 1 of the head of the stapler shown in the drawings is connected in a known way to a handle (not shown). Said anvil 8 and said circular blade 3 are intended to be progressively moved closer one to the other in order to cut the mucosa as the stapler head reach a closed position, that is when the rod 6 is progressively retracted into the central hole 5 of the second hollow stem 2 a by means of suitable rod retraction means (not shown in the drawings) which are included in the stapler handle, as it is known to a person skilled in the art. The circular blade 3 is moved forward by suitable blade moving means (not shown in the drawings) which are also included in the stapler handle, as it is known to a person skilled in the art. The edge 4 of the external goblet-shaped body 2 can be provided with suitable recesses 4 a which are designed to contain suitable suture means, such as for example metallic staples. In FIG. 2 the stapler head is shown in the open position and introduced in a hollow organ 9 through a hollow cylindrical introducer 10 being provided with flanges 10 a and 10 b.

The rod 6 has, according to the invention, one ore more annular grooves 11 which are spaced one from the other and formed on the lateral surface of the rod 6 perpendicularly to the axis thereof. Said annular grooves 11 are intended to receive in their inside a portion of mucosa 9 a of the hollow organ 9 which is included in a purse string suture (not shown) when the mucosa 9 a is tied around the rod 6. The number of annular grooves 11 and the distance between them are suitably calibrated in order to provide a plurality of fixing positions for the purse-string suture on the rod so as to be always able remove an amount of mucosa which is as large as possible.

The depth of the annular grooves 11 of the rod 6 is comprised between 0.5 mm and 3 mm, preferably it is about 1 mm. The cross-section of the rod 6 is preferably circular, but it can also be polygonal.

Each annular groove 11 of the rod 6 consists of a cylindrical surface 12, which has a smaller diameter than the rest of the lateral surface of the rod 6 and is connected thereto by a fillet surface 13. The radius of the fillet surface 13 between the cylindrical surface 12 and the rest of the lateral surface of the rod 6 is preferably about 1 mm.

In order to carry out the mucosectomy with the stapler according to the present invention, first a purse string suture is made in a prolapsing portion of mucosa 9 a to be removed from a hollow organ 9. The stapler head is then introduced in the hollow organ 9 in the open position, that is with the anvil 8 being spaced from the edge 4 of the external goblet-shaped body 1, by making the anvil 8 pass through the purse string suture. Subsequently the purse string suture is tied around the rod 6 between the edge 4 of the external goblet-shaped body 1 and the anvil 8. In particular the purse string suture is tied around the rod 6 in correspondence to an annular groove 11 which is formed on the rod 6 in such a way that the portion of mucosa 9 a being included by the purse string suture is laid therein without any possibility to slide along the rod 6. In order to remove in a controlled, homogeneous and exact way large amounts of mucosa, a determined annular groove 11 is selected among the annular grooves 11 formed on the rod 6 at a well calibrated reciprocal distance.

As it is shown in FIG. 3, the stapler head is finally closed by retracting the rod 6 in the central hole 5 of the stem 2 a of the internal goblet-shaped body 2, thus carrying the mucosa to be removed into the internal goblet-shaped body 2 and contemporaneously causing the anvil 8 to push the mucosa to be removed against the edge 4 of the external goblet-shaped body 1.

After closing the stapler head by suitable rod retraction means, suture means 14 are applied to the mucosa of the hollow body 9 in correspondence to the edge 4 of the external goblet-shaped body 1. For example, such suture means 14 can be metallic staples. Subsequently, the internal goblet-shaped body 2 and the circular blade 3 being integral thereto are moved towards the anvil 8, by suitable moving means, thus separating the mucosa contained in the internal goblet-shaped body 2 from the mucosa of the hollow organ 9 to which the suture means 14 have been applied. Finally, the stapler head is extracted from the hollow organ 9.

FIGS. 4, 5 and 6 show a second alternative embodiment wherein the stapler head is suitable to apply a fragmentable compression device. In this embodiment the anvil 8′ is a support for a component 14′ of the compression device to be coupled to complementary components 14″, 14″′, which are arranged in correspondence to the edge 4 of the external goblet-shaped body 1, when the stapler head is closed, as it is known to a person skilled in the art.

Preferably, during the mucosectomy the hollow body 9 is held open by means of a hollow cylindrical introducer 10, as it is shown in the FIGS. 2, 3, 5 and 6.

In order to illustrate the usefulness of the presence on the rod 6 of several annular grooves 11 and to highlight the biunivocal correspondence which is thus created between the distance of each individual groove 11 from the anvil 8, 8′ and the volume of mucosa to be removed, reference is made to the following non-limiting example of a stapler according to the present invention.

In a stapler provided with a circular blade 3 having a diameter of 24 mm and with a rod 6 having a diameter equal to 5 mm, 1 mm-deep annular grooves 11 are formed on the rod 6 thus, in correspondence to the grooves 11, the rod 6 has a diameter of 3 mm.

If an annular groove 11 was located in correspondence to the connecting point of the rod 6 to the anvil 8, 8′, when a purse string suture is tied around the rod 6 in correspondence to said groove 11, 21 mm of mucosa might be removed, that is two times the distance between the circular blade 3 and the annular groove 11, said distance being equal to the radius of 12 mm of the circular blade 3 minus the 1.5 mm radius of the rod 6 in correspondence to the groove 11.

In order to remove larger amounts of mucosa, it is preferable that the stapler is provided with three annular grooves 11 arranged at 10 mm, 20 mm and 30 mm respectively from the anvil 8, 8′. Such grooves correspond to about 29 mm, 45 mm and 63.5 mm of mucosa which can be removed. In fact, grooves 11 which are spaced from the anvil 8, 8′, when the rod 6 is retracted in the stem 2 a of the goblet-shaped body 2, allow to drag into said goblet-shaped body 2 a larger amount of mucosa, as the distance between the circular blade 3 and the annular groove 11 wherein the mucosa 9 a is fixed by means of the purse string suture increases, as it is shown in FIGS. 3 and 6. It is evident that the surgeon using the stapler according to the present invention can operate more rapidly, exactly and safely due to the present invention. 

1. A stapler for mucosectomy, comprising: a stapler head comprising at least one goblet-shaped body provided with a central hole wherein a rod is slidingly inserted, an anvil attached to an end of said rod opposite to said central hole, a plurality of annular grooves positioned on the lateral surface of the rod and perpendicularly to the axis thereof, the annular grooves being exactly spaced one from the other and suitable to receive a portion of mucosa to be tied around the rod in a purse string suture in correspondence of one of said grooves located at different distances from the anvil, whereby different amounts of mucosa can be exactly removed.
 2. The stapler according to claim 1, wherein the rod comprises three annular grooves.
 3. The stapler according to claim 2, wherein the three annular grooves are arranged at 10, 20 and 30 mm from the anvil, respectively.
 4. The stapler according to claim 1 wherein depth of the annular grooves is comprised between 0.5 mm and 3 mm.
 5. The stapler according to claim 4, wherein depth of the annular grooves is equal to 1 mm.
 6. The stapler according to claim 1, wherein the cross section of the rod is circular.
 7. The stapler according to claim 1, wherein each annular groove consists of a cylindrical surface having a smaller diameter than the remaining lateral surface of the rod and is connected by a fillet surface to the lateral surface of the rod.
 8. The stapler according claim 7, wherein the radius of the fillet surface between the cylindrical surface and the remaining lateral surface of the rod is 1 mm.
 9. (canceled)
 10. The stapler according to claim 1, wherein the at least one goblet-shaped body comprises an external goblet-shaped body and an internal goblet-shaped body, the internal goblet-shaped boy being smaller than the external goblet-shaped body and concentric with the external goblet-shaped body, wherein the central hole in which the rod is slidingly inserted is provided in the internal goblet-shaped body.
 11. The stapler according to claim 10, further comprising a circular blade connected with an edge of the internal goblet-shaped body. 